With many electronic integrated circuit devices and components such as the Land Grid Array (LGA) device used for computers and other apparatus, the numbers of contacts are relatively high. Moreover, the contacts are located in a planar array of high density, with the contacts frequently on centers as close as 0.050 inches. In traditional electronic interconnection practice, the normal forces required for providing a stable, low-resistance interface have been on the order of 100 grams for gold plated contacts and 300 grams for tin plated contacts, with a rather wide variation in normal forces dependent upon the environment of use. These requirements, when carried out with respect to as many as 100 or 200 contacts necessarily made simultaneously, entail overall closure forces ranging between 20 and 130 pounds to create considerable loads for the packages handling such components, particularly when viewed in the context of the very small and relatively fine plastic and metal structures involved.
In the aforementioned U.S. patent application related to a conductive gel area array connector and particularly in the disclosures therein, a type of conductive gel is employed wherein the forces of displacement of contacts into the gel or of the gel to flow into contact with the contacts are quite small, on the order of 20 grams per contact, including the normal force of the gel and the supporting plastic structure for the gel. This provides closure forces for gold-type contact systems on the order of 10 pounds or less, thus relieving the mechanical stresses involved in packages adapted to accommodate components such as LGA integrated circuits. With respect to the foregoing improvement, it was found that the surrounding and supporting plastic structure for the conductive gels was indeed the principal force generating structure, the gel itself having a normal force requirement much less than 15 grams.
A second aspect and problem relating to the aforementioned gel connector relates to the difficulty of handling gels in very small quantities in terms of controlling volumes of the gels and injecting such volumes into supporting structures.
The present invention has an objective of providing a gel connector of laminar construction requiring a very low force of engagement for interconnection as particularly related to area array electronic components such as LGA devices. It has as a further object the provision of an electrical connector utilizing conductive gels in conjunction with non-conductive gels to achieve a hydraulic interconnection of low force. It is yet a further object to provide a gel-type area array connector which is readily manufacturable by existing transfer processes.